1. Field of Invention
The present invention relates to a blood vessel engrafting system for repairing aneurysms and more particularly to a modular graft system for repairing aortic aneurysms by building a spring loaded graft within a blood vessel via percutaneous entry.
2. Prior Art
An aortic aneurysm is a very common deteriorating disease typically manifested by a weakening and expansion of the aorta vessel wall at a region between the aortarenal junction and the aorta-iliac junction. An aneurysm affects the ability of the vessel lumen to conduct fluids, and may at times be life threatening, for instance, when rupture of the vessel wall occurs. A standard treatment for repairing an aneurysm is to surgically remove part or all of the aneurysm and implant a replacement prosthetic section into the vessel. Such surgery, however, is generally postponed until the aneurysm has grown to a diameter greater than five centimeters. With aneurysms over five centimeters in diameter, the risk of complications is greater than the risk inherent in surgical excision and grafting of the aneurysm. Consequently, aortic aneurysms measuring greater than five centimeters in diameter, and those showing rapid increase in size, are generally surgically engrafted as a matter of course, before rupture occurs.
The standard procedure for repairing an aortic aneurysm requires one or two days of preparing the large and small intestines prior to hospitalization. The operation itself generally takes one to three hours to perform, and necessitates several units of blood for transfusion. The patient commonly remains hospitalized for several days following surgery, and requires as much as three months recuperation time before returning to work.
Moreover, there remains a significantly high rate of mortality and morbidity associated with the standard procedure. The mortality rate is as high as 8%, while the morbidity rate includes incident complications such as blood loss, respiratory tract infections, wound infections, graft infections, renal failure, and ischemia of the bleeding intestine. The mortality and morbidity rates for this type of major surgery are also often influenced by the fact that the typical aortic aneurysm patient is elderly and, therefore, less able to withstand major surgery, including anesthesia.
Other treatments for repairing an aneurysm involve deploying a graft device at the aneurysm site via a catheter traveling through a femoral artery. Conventional tubular aortic replacement sections, however, are generally considerably larger in diameter than the femoral artery and, therefore, cannot be inserted through the femoral artery lumen to the site of the aneurysm.
Even in the more advanced aortic graft assemblies which enable percutaneous deployment and placement of a spring loaded graft for a non-surgical correction of an aortic aneurysm, the required entry profile requires at least 10-12 FR. This is the case since at a minimum these graft systems are comprised of graft material, two or more spring stents, a balloon catheter, a sheath introducer, and plunger for deployment of the graft.
Thus, there exists a need for treatment of an aneurysm utilizing a system enabling deployment and placement of an aortic graft which is much smaller than that used in conventional practice and, thus, able to facilitate a much smaller entry profile.